/ Dictionary / Index P perp: Meaning and Definition of Find definitions for: perp Pronunciation: (pûrp), [key] — n. Police Slang. the perpetrator of a crime. perp. Pronunciation: [key] perpendicular. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. peroxysulfuric acid perpend Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language